1. Field of the Invention
The present invention relates to a motor, more particularly to a motor with a rotor positioning component.
2. Description of the Related Art
Referring to FIG. 1, a conventional motor 1 includes a base 11, a circuit board 12, a rotor unit 13 and at least one rotor positioning component 14.
The circuit board 12 has two induction coils 121 and a sensor unit 122. The rotor unit 13 includes a magnet carrier 131 rotatable relative to the base 11, and a permanent magnet unit 132 disposed on the magnet carrier 131. The permanent magnet unit 132 is in a shape of a ring and has a plurality of magnetic pole regions 133 that are angularly disposed with respect to a rotation axis (L) of the magnet carrier 131. Adjacent ones of the magnetic pole regions 133 have opposite magnetic polarities and form a border region 134 that extends radially with respect to the rotation axis (L). Magnetic strength at the border regions 134 is weaker than that at the magnetic pole regions 133. The rotor positioning component 14 is disposed on the circuit board 12 adjacent to the rotor unit 13, and is capable of magnetic attraction with the magnetic pole regions 133 of the permanent magnet unit 132.
The induction coils 121 are operatively associated with the permanent magnet unit 132 to generate a magnetic repulsion force for driving the rotor unit 13 to rotate relative to the base 11 about the rotation axis (L). When the induction coils 121 cease to generate the magnetic repulsion force to stop driving further rotation of the rotor unit 13, the magnetic attraction between the rotor positioning component 14 and one of the magnetic pole regions 133 of the permanent magnet unit 132 prevents the sensor unit 122 from overlapping with a projection of any one of the border regions 134 on the circuit board 12 once the rotor unit 13 stops rotating, thereby facilitating subsequent activation of the rotor unit 13.
However, since the rotor positioning component 14 is disposed between the circuit board 12 and the rotor unit 13, jamming of the rotor unit 13 may occur due to undesired removal of at least a part of the rotor positioning component 14 from the circuit board 12 after long-term use or as a result of vibration of the rotor positioning component 14 when the motor 1 is operational.
Moreover, while modifying the rotor positioning component 14 to be disposed on the base 11 and between the base 11 and the circuit board 12 may alleviate jamming of the rotor unit 13, vibration of the circuit board 12 while the motor 1 is operational may lead to short-circuit between the rotor positioning component 14 and the induction coils 121. While an insulation material may be applied on the rotor positioning component 14 to avoid such short-circuit, additional manufacturing time and costs will be incurred.
Furthermore, even though configuration of the rotor positioning component 14 may prevent the sensor unit 122 from overlapping with a projection of any one of the border regions 134 on the circuit board 12 once the rotor unit 13 stops rotating, the sensor unit 122 may not appropriately overlap with a projection of one of the magnetic pole regions 133 on the circuit board 12. As a result, subsequent smooth activation of the rotor unit 13 may not be guaranteed.